This is all age dependent and without knowing your age, it's impossible to answer.

Me, I've lost a total of 170lbs in two separate dieting periods from age 40-45 (not through IF, I tried IF and found it wasn't sustainable long term and if anything, long term it's quite dangerous) and I have a lot of loose skin all over my body.

The loose skin doesn't tone up, go away or get better with age, the skin just loses its elasticity and nothing will change that except an expensive surgical operation to remove it altogether, leaving you with graphic scars. I know someone that's had it.

If you're in your twenties then you're in luck, there's a very good chance you can recover and it won't look as bad.

But mid to late thirties onwards and forget it, you're stuck with it.